<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <script>
    function getMax(arr){
      var result = arr[0]

      // 验证
      for(var i = 1; i < arr.length; i++) {
        if(arr[i] > result) {
          result = arr[i]
        }
      }

      return result
    }

    var max = getMax([10, 3, 2, 5, 4])

    console.log(max)
  </script>
</body>
</html>